1. Field of the Invention
The present invention relates to an optical recording/reproducing device of a wobble structure, and more particularly, to method and device for controlling an optical recording/reproducing device, in which a wobble signal is detected at a time when an optical recording medium is not in a regular recording/reproducing state, and is used in a regular recording/reproducing state.
2. Background of the Related Art
In general, a rewritable optical recording medium, particularly, DVD-RAM, a rewritable optical disk, is provided with signal tracks of land and groove, for facilitating a tracking control even for an empty disk without any record of information signal. Recently, information signals are recorded on the lands as well as grooves respectively for increasing a density of recording. At the outset, neither control of, nor recording on the rewritable disk is possible as there is no information recorded thereon. Therefore, disk tracks are formed on the lands and grooves, information is recorded along the tracks, and information for random access and rotation control is recorded on the disk separately, for making the tracking control possible for an empty disk without any information signal recorded thereon. In this instance, the control information may be recorded at a header region at a start of every sector after pre-formatting the header region, or along the tracks in a wobbling form. The wobbling is recording of address information on a boundary surface of a track by using a fixed frequency or frequency modulation/phase modulation FM/PM for enhancing address recording or control.
In order to record or reproduce information at the optical recording device, the tracking and focus control are made through an optical pickup. FIG. 1 illustrates a block diagram of a related art optical recording/reproducing device, wherein the signal track of the optical disk 101 is provided with lands and grooves, for recording/reproducing data to/from, not only the land or groove tracks, but also both the land/groove tracks. There is an optical pickup 102 for directing an optical beam focused by an object lens to a signal track of the optical disk 101 under the control of the servo controlling part 106, and for receiving an optical beam reflected at a signal recording surface, focusing by means of the object lens again, and directing to an optical detector for detection of a focus error signal and a tracking error signal. The optical detector is provided with a plurality of optical detecting elements, each for providing an electrical signal proportional to a quantity of light obtained therefrom to a RF and servo error generating part 104. The RF and servo error generating part 104 combines the electrical signals, to generate a RF signal required for reproducing data, and a tracking error signal TE and a focus error signal FE both required for servo control, and the like. The tracking error signal TE is a signal generated by processing a read channel 2 signal, such as filtering and the like, and the RF signal is sometimes called as a read channel 1 signal. The RF signal is provided to a decoder 105 for reproduction, the servo error signals, such as FE and TE, are provided to the servo controlling part 106, and the control signals for data recording are provided to an encoder 103. The encoder 103 encodes a data to be recorded into recording pulses of a format the optical disk requires, and records the data on the optical disk 101 through the optical pickup 102, and the decoder 105 restores the RF signal into an original form of data.
In the meantime, there may be a host, such as PC, connected to the optical recording/reproducing device, for providing a recording/reproducing command to the microcomputer 111 through an interface 110, and the data to be recorded to the encoder, and provided with a reproduced data from the decoder 105. The microcomputer 111 controls the encoder 103, the decoder 105 and the servo controlling part 106 in response to recording/reproducing command from the host. In general, the interface 110 is an ATAPI (Advanced Technology Attached Packet Interface). That is, the ATAPI is an interface standard between optical recording/reproducing device, such as CD or DVD drive, and the host suggested for transferring a data decoded at the optical recording/reproducing device to the host, wherein the decoded data is converted into a protocol of a packet form for making the data to able to be processed by the host.
In the meantime, the servo controlling part 106 processes the focus error signal FE to generate a driving signal for controlling focus and provides the driving signal to the focus servo driving part 107, and processes the tracking error signal TE to generate a driving signal for tracking control and provides to the driving signal to the tracking servo driving part 108. The focus servo driving part 107 drives a focus actuator in the optical pickup 102, to move the optical pickup 102 in an up and down direction, so as to follow the up and down movement of the optical disk 101 while the optical disk 101 rotates. The tracking servo driving part 108 drives a tracking actuator in the optical pickup 102, to move the object lens of the optical pickup 102 in a radial direction, for correction of a beam position to follow a required track. The servo controlling part 106 detects rotation speed information of the disk from the RF signal and provides to a spindle servo 112. The spindle servo 112 subjects a spindle motor 113 to Phase Locked Loop (PLL) control in response to the rotation speed information, for rotating the disk 101. That is, the spindle motor 113 exerts a rotating force to a spindle (not shown), and the spindle transmits the rotation force given from the spindle motor 113 to the disk 101, for rotating the disk 101 at a desired speed.
In the meantime, as the servo is unstable before starting a regular tracking or just after seek, the optical recording/reproducing device can not track on at once. Therefore, in this case, it is required for the optical recording/reproducing device to run freely (i.e., the tracking servo is turned off, while the focus servo only is turned on) until an appropriate condition is reached. Then, the servo controlling part 106 runs the spindle at an appropriate speed after the free running, puts the tracking servo into operation, and attempts a wobble PLL. Consequently, the method has a problem in that performance of the optical recording/reproducing device is poor as the servo is stabilized after the free running.